They are unbeaten in Norway's Tippeligaen and are the hot favourites to earn a two-legged crack at United in the third and final round of the Intertoto Cup.
Newcastle know that victory in that tie would see them into the second qualifying round of the UEFA Cup. For now, though, it will be a case of wait and see for United and Roeder, with the first leg of the first round of the competition to start on June 17 and the second leg taking place a week later.
Irish side Dugannon Swifts play Icelandic outfit IBK Keflavik. Keflavik started their season with a 2-1 defeat against Vestmannaeyjar but would be strong favourites to beat Dugannon, while Lillestrom in turn should have no problems overcoming the men from Iceland.
Lillestrom are managed by former Boro striker Jan Age Fjortoft, and head coach is ex-Man City and Southampton man Uwe Rosler.
Roeder: "Football can throw up some funny results but I think in my own mind we will play Lillestrom. I have already checked out how they are doing this season and checked on each player. I am aware they are a decent team. They are halfway through their season and will be very fit and we must be prepared for that.
"The first tie is at home and we want to get off to a good start at St James'. As I say, you can get results that will surprise you. But I would have thought they would be too strong for the team from Northern Ireland or Iceland."
Lillestrom will take on the winners of the first-round game on July 1 and July 8. And United's first leg will be on July 15, with the return on July 22.